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Textured Surface for Magnetic Disks

IP.com Disclosure Number: IPCOM000112314D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Brady, MJ: AUTHOR [+5]

Abstract

If the domain walls in a thin magnetic film can be pinned to features on the underlying surface that are of the same size (about

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Textured Surface for Magnetic Disks

      If the domain walls in a thin magnetic film can be pinned to
features on the underlying surface that are of the same size (about

100A), the motion of the domain walls is hindered, and the material
is better as a recording medium.  The B_H loop is more square.

      A polyimide surface, where the polyimide is a morphological
composite material formed by the phase separated mixture of two
polyimide precursors such as polyamic acid and polyamic acid ester,
has been shown to have a surface texture which can be controlled by
controlling the initial deposition of the polyimide material.  In
particular, the surface can be made to have "peaks" or "valleys" of
depth or height in the region of 100A.

      We disclose that we can spin on such polyimide precursor
material on to glass or metal substrates, imidize the material, and
then can transfer the topography of the surface to the surface of the
glass or metal by reactive ion etching.

      If the reactive ion etch is appropriately chosen, the amplitude
of the surface texture can be increased by the etch rate ratio
between the substrate material and the polyimide.  For example, the
etch rate of glass using a SF&sub6.  plasma is much higher than that
of photoresist, which should be about the same rate at that of
polyimide.

The method of manufacture of such magnetic material is to:

1.  Spin on mixture of polyimide precursors on metal or glass disks
    used in presen...